1. Technical Field
The present disclosure relates to a semiconductor package and an electronic component package, and more particularly to a semiconductor package in which an IC chip mounting a driver transistor is mounted on leads by flip chip bonding and sealed with resin, and an electronic component package incorporating the semiconductor package.
2. Description of the Background Art
Conventionally, in semiconductor packages in which integrated circuit (IC) chips are sealed with resin, a wire-bonding technique is used to electrically connect pads of the IC chip and leads of the semiconductor packages.
Alternatively, there is also a flip chip bonding technique in which the IC chip is mounted in a device by using projecting solder terminals called bumps arranged in a grid array. Since the flip chip bonding technique can reduce the mounting area of the IC chip compared to the wire-bonding technique, the external dimensions of the semiconductor package can be downsized when the semiconductor package is assembled with the flip chip bonding.
There are ICs that have large mounting areas, such as voltage regulator ICs mounting a driver transistor and ICs mounting a power transistor. Herein, the term “large-area transistor” means, for example, a transistor constituting an analog circuit (e.g., a reference voltage generator, a differential amplification circuit, or a buffer circuit) and a transistor whose layout area of the transistor is greater than that of transistor used to configure a digital circuit. In a semiconductor package as proposed in JP-2005-228811-A, for example, an IC chip mounting a power transistor is mounted on a wire substrate (wiring patterns) using flip chip bonding.
However, the IC chip installing large-area transistors such as a driver transistor or a power transistor generate heat caused by the transistors, which is a problem.
In an effort to counteract this problem, in a configuration in which the pads of the IC chip and the leads of the semiconductor package are electrically connected by wire bonding as proposed in JP-2006-196922-A and JP-2006-332708-A, because the IC chip is mounted on a die pad, heat radiation can be improved by exposing the die pad outside an encapsulating resin.
By contrast, in the semiconductor package assembled with flip chip bonding, the IC chip is mounted on the leads in a state in which a pad formation face of the IC chip faces the package leads. Therefore, in order to improve heat radiation, in a semiconductor package like that proposed in JP-2005-228811-A, the IC chip is not sealed with resin but with a heat releasing member formed of metal material connected to a back face of the IC chip.
However, sealing the semiconductor package using metal material is more complicated than resin sealing, and consequently the cost manufacturing a metal material-sealed semiconductor package is higher than that for a resin-sealed semiconductor package.